Noblesse.....Main lead is silent and epic badass(You can bet for it!) and second main in lead is also cool and badass but he is the devoted follower of the first.....Hey you should give it a chance atleast till chapter 77 where main epicness starts with new evolved art.

Fulfill all requirement: No. 6 (novel)Fit perfectly. There are also anime & manga version of it, but I recommend you to read the novel version. Adekan- must read, contain slashKarneval- Nai isn't "calm\silent\not very talkative\\maybe looks nerdy" that turn out to be "very strong\badass\good looking\smart\good", but he does have unique ability.